Feeding mechanism for sewing machines



July 1931- c. w. MUELLER FEEDING MECHANISM FOR SEWING MACHINES FiledApril 26, 1927 5 Sheets-Sheet 1 A TTORNE Y.

July 7, 1931. c, w, MUELLER 1,812,895

FEEDING MECHANISM FOR SEWING MACHINES Filed April 26, 1927 5Sheets-Sheet 2 47 w 'r l/ I Hd''\9 //0 T" t; 27 55 i v 35 54' IT? (i Z4I July 7; 1931. 'w MUELLER 1,812,895

FEEDING MECHANISM FOR SEWING MACHINES Filed April 26, 1927 sSheets-Sheet 5 4 N 2 H Q Q i n o I j i q I l \D fi \iw i I 1 0 $3 I I ll I b z\ I m f ,l x {I Q & I x I \3 1 4 3 f m 1; Q a w b Q I I (q @3INVENTOR. 'Cfiar sWMzeZZa;

"5555 f 177 15555 I "707T ATTORNEY.

C. W. MUELLER FEEDING MECHANISM FOR SEWING MACHINES Filed April 26,1927' 5 Sheets-Sheet 4 1 t I Mud- July 7, 1931. c. w. MUELLER FEEDINGMECHANISM FOR SEWING MACHINES Filed April 26, 1927 5 Sheets-Sheet 5 I.YVEN TOR. CfiarZesWlfudla;

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2 m6 m9 vm2 Patented July 7, 1931 UNITED STATES PATENT OFFICE CHABLESW.MUELLER, 0F: SILLOUIS, MISSOURI, ASSIGNOR TO LEVIIS INVISIBLE STITCHMACHINE-1 COMPANY, OF ST. LOUIS, MISSOURLiS CORPORATION OF MAINE FEEDINGMECHANISM FOR SEWVING MACHINES Application filed April 26,

This invention relates to new and useful improvements in feedingmechanisms for sewing machines generally, although the invention is moreespecially directed to a feed- 5 ing mechanismfor use in blind stitchsewing machines used in felling operations.

One of theprincipal objects of the invention is to provide upper andlower feeding mechanisms for intermittently feeding su- :perpose-dlayers of materials .past'a stitch forming mechanism, the upper layerhaving its marginal edge portion infolded and \disposed in asubstantially vertical plane for engagement by the upper feed dogwhereby both the base layer and the foldedupturned edge portion of theupper layer will be simultaneously fed Without having a drag imparted tosaid folded upturned'edge portion of the upper layer.

Another object of the invention is to provide upper and lower feedingmechanisms of the character described, together with means forwithdrawing both the upper and lower feed dogs from operative positionswhereby the material or work maybe either inserted in themachine orwithdrawn therefrom.

W ith these and other'objects in view which will more fully appear, thenature of the invention will be more clearly understood by followingthe. description, the appended claims, and the several viewsillustratedin the accompanying drawings.

Inthe accompanying drawings which illus- 5 irate one form of myinvention,

Figure 1 is a, front elevation of the stitching head and the work armwhich form parts of a blind stitch sewing machine equipped with .myinvention,

Figure 2 is a left handelevation thereof, Figure 3 is a rear elevationof the machine. Figure 4 is a perspective view of the upper feedmechanism and the associated parts,

Figure 5 is a plan view of the cam for operating the upper feed dog,

Fi ure 6 is an enlarged sectional W'ew 'showingthe means for permittingthe lower feed dog to be depressed,

Figure .7 is an end elevation showing the normal position ofthe'lowerfeeddogin full 1927. Serial No. 186,673.

lines and the depressed position of the dog in dotted lines,

Figure 8 is a perspective view of the operating lever for depressing thelower feed Figure '9 is an enlarged top plan view of the main presserfoot showing the upper feed dog associated therewith,

Figure 10 is a bottom plan view thereof,

Figure 11 is a transverse sectional view taken on the line ll11 ofFigure 9,

Figure 12 is a perspective view of the upper feed dog and feed bar, and

' Figure 13 is a side elevation of the main presser foot showing theshank of the upper iced dog supported in a guide fixed to said oot.

Like reference numerals designate corre sponding parts throughout thefigures of the drawings.

Referring to the accompanying drawings, I have shown in Figure 1 a baselayer A which may be-the body fabric of a coat and a superposed layer Bwhich may be the lining therefor. The present invention is especiallyadapted for felling the lining B to the base layer or body fabric A, andto this end the superposed layer B has its marginal edge portioninfolded as shown at b, and turned up into a vertical plane, asindicated at b. By means of the sewing machine illustrated in theaccompanying drawings, a line of blind stitches is formed which is.disposed adjacent the meeting point between the base layer A and theupturned portion 5 of the superposed layer, these stitches serving tojoin the two layers along a line parallel with the folded edge of thesuperposed layer. After the stitching operation, the upturned foldedportion of the superposed layer is returned to normal or horizontalposition, thus covering the line of blind stitches formed by saidstitching operation.

The blind stitch sewing machine shown in the accompanying drawings is ofthe Lewis type and comprises a frame which includes a base 5, alaterally extending work arm 6, a standard 7 an overhanging arm 8, and astitching head 9 which is secured to the free 611(1- Of the overhanging8 and dis stitching head 9 and is adapted to be driven posed above theouter end of the work arm 6.

The machine includes a stitch forming mechanism which I have indicatedas a whole by the reference numeral 10, and a work presenting mechanismwhich I have indi- '8 and across the standard 7. A grooved pulley 13 isfixed to the. shaft 12 opposite the by any suitable power.

The work presenting mechanism is shown and .claimed'in my co-pendingapplication Serial No. 186,674, filed April 26, 1927 This -workpresenting mechanism includes a main presser foot 14 whichis fixed tothe stitching head 9, a work clamp 15 which cooperates with the workbelow the main presser foot, -a lower feeding mechanism '16, an upperfeeding mechanism 17,: alower plunger mechanism 18, an upper plungermechanism and a movable presser foot 20.

The stitch forming'mechanism '10 includes will be oscillated along thestub shaft 24 -shaft;24 secured to the stitching head 9. The

needle lever 23 is mounted on the stubazshaft 24, not only foroscillatory movements about said shaft, but also for lateral movementslongitudinally of said shaft. The other arm of the needle lever 23 ispivotally connected with the lower end of a link 27 the upper end ofsaid link being pivotally connected as at 28 to one arm of a bell cranklever 30 which is journaled on the stitching head 9,

the other arm 31 of the bell crank lever being pivotally connected as at32 with the lower end of a link 33. The upper end of the link '33 isconnected to an eccentricpin 34 formed on a jack shaft 35 which isjournaled in the stitching head 9 below the mainshaft 12 and extends inparallelism therewith. A 1 to 1 gear coupling 35 connects the main shaft12 and the jack shaft 35 and consequently during each complete rotationof the main shaft 12 the needle 21 is thereby given a completereciprocation in the line of feed.

It is desirable to impart a shogging motion to the needle 21 whereby theneedle during one reciprocation will enter the base layer and emergetherefrom and whereby during the following reciprocation theneedle willenter. the folded upturned portion ofthe lining. To this end, I haveprovided the following mechanism which will impart a positive lateralshifting movement to the needle lever 23: 7

The needle lever 23 is formed with a hub extension 36 journaled on thestubshaft 24 and this hub extension is formed with a pcripheral groove37 which receives a slide block 38 secured to the lower end of an arm 39of a bell crank lever 40, said lever 40 being fulcrumed as at 41 to thestitching head 9. The other arm 42 of the bell crank lever is providedat its outer end with a fork 43 for engagement with an actuating cam 44.The cam 44 is fixed to a shaft 45 which is journaled in thestitching'head 9 and has its longitudinal axis disposed in parallelismwith the line of feed. The cam shaft 45 is rotated once to every tworevolutions of the main shaft 12. In order to thus rotate the cam shaft45, I have journaled a substantially vertical shaft 46 on the stitchinghead 9, and this shaft 46 is driven from the gear coupling 35 throughthe medium of'a gear 47 fixed to said shaft 46. Fixed to the shaft 46 isa worm 48 which drives a pinion 49 fixed to the cam shaft 45. The cam 44is of the peripheral type and includes-two separated concentricportions. These concentric portions while. the needle is in its forwardposition.

The cam shaft 45 rotates in an anti-clockwise direction as viewed fromthe front of the --machine .and consequently when one concentric portionis disposed above the axisof the cam shaft, the bell crank lever 40 isin a position whereby the needle will reciprocate in its lefthandpositiomwhereas when the other concentric portion of the cam is abovethe axis thereof, the bell crank 40 will be shifted so that the needlewill reciprocate in its righthand position.

Cooperating with the needle 21 to form a line of straight-away stitchesis a rotary hook 52, and this hook is given two complete rotations toeach reciprocation of the needle.

The hook is fixed to a shaft 53 (see Figure and fixed tothis shaft is abevel gear 54 which is driven from a corresponding bevel gear 55 fixedon the vertical shaft 46. Inasmuch as the gear coupling 5455 is a 1 to 1coupling, the hook 52 will be rotated once during each rotation of thevertical l shaft 46.

The presser foot 14 is fixedly secured to the lower portion of thestitching head 9,-and cooperating with the under face of the presserfoot is the work clamp 15, the lower feed .mechanlsm 16, and the lowerplunger mechanism 18.

The lower feeding mechanism 16 includes .a feed dog 56 whichis of the4-motion type,

and the mechanism for operating this feed dog is substantially identicalwith that shown 1n my former Patent 1,588,132, issued June 8, 1926. Thebackward and forward movement of the feed dog is obtained through themedium of a rock shaft 57, which'I term the fe d trave sha t, a ditheup, an do n im VQmEIJ Qf the :feeddog is. Qbtained fromarocikshaft-58,.Whi h1 te. ?m.- h f e lif shaft. These rock shafts- 57,5.8,eXtendlon- .git dinal yw thin h Work-arm; G n a e their righthandends journaled in a bearing lug 59 and theirlefthand ends j ournaled inbearings formed in ablock60 which is de- ,tachably secured tothelefthand .end ofzthe work var nby screwsfil. Fixedto the outer endofrthe ffeed travel shaf 57 is a rock 1 arm .62, and .pivotallyconnecting the outer ,lendsiof the rock arm and the forward extremityvofthe feed dog 56 is a link-63. The rock varm 62 ,extendsin ageneralvertical direction and. thelink extendsin ageneral horizontaldirection. Thus upon movement of the rock arm.62, thelink 6-3 willimpart back- .wardand forward movements tothe feed -20.

as at. 651, to; the; upper; end of a substantially dog-56. Thefeeddog'is pivotallyconneoted,

vertically disposedlink-65, the lower end of theglink,beingpivotallyconnected, as at 66, tothe horizontal arm 67 of abell crank lever68-,.;the v.ertical arm 69 of thebellcrank lever being ,pivotallyconnected as; at 7 O to one end ofja link;71, the other end of said link71 being pivqtally connected as at ;72,to the outer end ,of'a verticallydisposed rock arm 7 3 fixed to thefeed'lift shaft; 5.8. In order tomaintain the feed surface of the feed dog in a substantially horizontalplane during the sfeed.movements thereof, I have provided a -,spring 7 iwhich is connected by a pin 75 fiXedtO thelink 65 and a pendent tail 76fixed to the feed dog. ;It vwill, therefore, be observed that uponrocking movement of the feed lift shaftfisathe vertical link 65 Will bebodily raised and lowered, and consequently the feed dogwi-ll be givenitsup and down movements. By proper timing of the shafts 57 and 5 8,,a1-way feedmotion will ;be imparted to said I dog.

The bell crank lever 568 is pivotally connected, as at 7:7 toa head 78secured to the lowe d o a g1 dep st7 sa d ea a 2post :fQrming avertically movable carrier.

{The post 7 9'gis mounted for V rtical sliding moyements-inabore formedinthe end-block 160, andithisblockisformed with aseat- 80 for engagementby-the head 78 to limit theup- JVard-Inovement of the carrier. Thecarrier ,isnorm ly el in it highe p si-t mt is, withthe head -78 bearingagainst-the seat 80,-b.y mean of a fi sp ing-8 th i ne .e dof hich igidly s u e ath Wor arm 6; and the outer end thereof is disposed underthe head 7850 as to yieldably .retain .the carrier inits higllestposition. The upper find .ofthe 081 37 9 projects above theblock 6O andv carries a pair of rearwardly projecting ar-ms 82f82 between whichispivoted, as at 6. the w rk c mp 1 E ren- 1, the f regOi-Dg, it Will beobserved that when the feed.- dog 6 elevated t its high- ,est position,the fulcrumof the bell crank -;lever'.68 is then shifted to the pivot66, and consequently the last part of the rocking .movement of the crankarm 73 will cause the .bell crank lever 68to be moved downwardly aboutitsfulcrum 66, thus lowering the work clamp 15. The parts are so timedthat the work clamp islowered prior to the feeding movement of the feeddog. The reverse order of movement will take place at substantiallythetimethe feed dog reaches the end of its feeding stroke, thus causingthe clamp to engage the fabric and clamp the latter against thebottom ofthe main presser foot14c so as to retain the fabric against movementwhile the needle is penetrating the material and emerging therefrom.

In order to rock the feedtravel shaft 57 and the feed lift shaft 58, Iprovide the main shaft 12with two eccentrics. A con .nection rod '84:has itsupper. end engageable with one of said eccentrics and has itslower end pivot-ally connected to a rock arm fixed to the feed travelshaft 57. A connection rod 87- has its upper end engageable withtheother eccentric mounted on the main shaft and has its lower endpivotally connected to arock arm fixed to the feed lift shaft 58. .Theconnection rods 84 and87 are disposed within the standard 7 of themachineframe, and the eccentrics which are mounted on the main shaft-foractuating these rods are timed so as to bring about a ti-motion movementto the feed dog.

In order to position the baselayer A whereby the needle 21 willpenetrate and emerge therefrom, I have provided the lower plungermechanism 18 which includes a vertically reciprocatory plunger 91 whichis disposed directly below an opening 90 formed in the presser footltand directly below the stub shaft 24 which supports the needle-lever23. The plunger 91 is reciprocated vertically through the medium of aplunger shaft 92 which is journaled in and extends longitudinally ofthework arm 6, said plunger shaft 92 being oscillated by the main shaft 12through the mediumof aconnection which I have indicated as a wholeby thereference numeral 93. This particular plunger operating mechanism formsthe subject matter of my vco-pending application, Serial No. 186,672,filed April 26, 1927, and it is there fore believed that furtherdescription will be unnecessary.

The main presser foot 14 includes a heel 94 ,and a toe 95, the opening90 being located the-rebetween. The foot 14 includes at its front end anoffset portion 96 which is spaced from the toe to form a longitudinallyex tending and vertically disposed guideway 97 for the upturned foldedportion Z) of the lining B. This guideway extends in the line of feedand includes a vertical wall 98 which is on thelefthand side of the pathof needle.

oscillation. The wall 98 extends rearwardly 1 past the opening 90 andterminates in the heel 94, as indicated at 99 in Fig.10. Cooperatingwith the guide wall 98 is the horizontally movable presser foot 20 andhorizontally movable upper plunger 100, the foot 20 extendingsubstantially across an opening 101 formed in the wall 98 and theplunger 100 being mount-ed for reciprocatory movements through saidopening 101 to project the node 'of the upturned folded portion Z) intothe path of needle oscillation. Inasmuch as the 7 of the presser foot 14whereby the said teeth I specific construction of the movable presserfoot 20, the upper plunger 100, the means for withdrawing said movablepresser foot 20 from operative position, and the means for actuating theupper plunger is shown, de-

scribed and claimed in my 'co-pending application above mentioned,Serial No. 186,672, it is thought that further description of theseparts will be unnecessary.

i The upper feed mechanism 17 includes a feed dog102 which is connectedto the feed bar 103 having an upwardly extendingand will cooperate withthe guiding wall 98 and clamp the upturned folded edge portion 6therebetween. The feed dog is supported for 7 its horizontal movementsby means of a guide 106 which is attached to the lefthand side of thepresser foot 14, said guide including upperand lower horizontal arms 107and 108 respectively for receiving the shank of the feed dog 102.Forimparting backward and forward movements to the feed dog 102, thatis, movements in the line of feed, I have provided an actuating lever109 which is fulcrumed on a horizontal pivot 110 fixed to the stitchinghead 9. The lower arm 111 of said lever is connected to the rear end ofthe feed bar 103 through the medium of a horizontal. pivotalconnection112, and a vertical pivotal connection 113. The upper arm 114 of saidlever is provided with a segmental slot 115 to which is adjustablyconnected as at 116 the rear end of alink 117 which has its forward Iend pivoted to an eccentric pin 119 fixed to the shaft 35.Consequently," during each complete rotation of the main shaft 12, the

lever 109 will be given a complete reciprocation, and as a result thefeed dog 102 will be given its backward and forward movements. In orderto reciprocate the feed dog 102 laterally, that is, toward and away fromthe upturned edge portion Z) of the lining B, I have provided anactuating lever 120 which is vertically disposed and is mounted tooscillate in a plane at right angles to the lever 109. The lever 120 isprovided at its lower end with a groove 121 for continuous althoughsliding contact with the guide plate 104 carried by the feed bar 103 soas topermit said feed bar to'move longitudinally in the line of feed.The lever 120 is fulcrumed intermediate its ends on a crank pin 122fixed to a crank shaft 123 journaled in the stitching head 9. The crankshaft has its longitudinal axis in the line of feed, and secured to therear end of this crankshaft is a rock arm'124. A spring 125 has one endfixed'to the rock arm 124 and the other end fixedto the stitching head9. The upperend of the actuating lever 120 carries a roller 126 forengagement with a peripheral cam 127 fixed on the shaft 45. The cam 127is provided with oppositely disposed high points or concentric portions128128 and opposed intermediate eccentric portions 129129, the formerhaving a common radius. A spring 130 has one end connected to the upperarm of the lever'120 and the other end connected to the stitching head9. The spring 130functions to yieldably retain the-cam roller 126in'constantengagement with the actuating cam 127. The spring 125serves'to yieldably retain the cam shaft '123'against movement, andconsequently yieldably retain the fulcrum of the lever 120 againstmovement. 7 I

Thus "when a seam or other abnormally thick portion in the upturnedfolded portion 6 of the lining is being fed through the machine, thefulcrum 122 of the lever 120 will yield and thereby avoidany chokingaction to the feed of the material which would otherwise occur by reasonof the guiding wall 9 being immovable. V I

In order to depress the lower feed dog 56 from working position relativeto the presser foot 14, and to simultaneously withdraw the upper feeddog 102 laterally away from working position, I have provided thefollowing manually controlled mechanism In order to permit the work tobe inserted in the machine or to be withdrawn therefrom, it is'desirableto provide means for depressing the lower feed dog 56 from co-operativerelation with the main presser foot 14 and to move the upper feed dog102 laterally away from the 'fixed guiding wall 98. I have, therefore,provided a manually operable means for this purpose. This manuallyoperable means includes a lever 131 which is journaled on the plungeroperating shaft 92 through the medium of two bearing arms 132-132. Thelever 131 extends longitudinally of the work arm 6 and has its outer endprovided with an offset projection 133 which engages directly above thehead 78 of the post 7 9 to which the bell crank lever 68 of the lowerfeed mechanism is pivoted. The inner end of the lever 131 is providedwith an operating extension 134 which is normally disposed ing a; feeddog, means for reciprocating said bar-longitudinally in'the linev offeed, an oscillatory shaft extending parallel to the line of feed'andhaving a crank pin, a lever fulcrumed on said crank pin and having oneend operatively connected to said feed bar for reciprocating the latterin a plane at substantially right angles to the longitudinal axis of thefeed bar, and means for oscillating said shaft to shift the fulcrum ofthe lever for moving the feed dog out of operative working position.

7. In a' feeding mechanism for sewing machines, the combination with afeed bar having a feed dog, means for reciprocating said barlongitudinally in the line of feed, an oscillatory shaft extendingparallel to the line of feed and having a crank pin, a. lever fulcrumedon said crank pin and having one end operativelyconnected to said feedbar for reciprocating the latter in a plane at substantially rightangles to the longitudinal axis of the feed bar, means for yieldablyretaining said shaftagainst oscillatory movements, and means foroscillating said shaft against the tension of said yieldable means toshift the fulcrum of the lever for moving a the feed dog out ofoperative working position.

8. In a feeding mechanism for sewing machines, the combination with afeed bar having a feed dog,-1neans= for reciprocating said barlongitudinally in'the line of feed, an oscillatory shaft extendingparallel to the line of feed and having a crank pin, a lever fulcrumedon said crank pin and having one end' operatively connected to saidfeedbar for reciprocating the latter in a plane at substantially rightangles to the longitudinal axis of thefeedbar, means for yieldablyretaining said shaft against'oscillatory. movements, means foroscillating said leverin cluding avperipheral cam having direct contactwith the other end of the lever, a spring for maintaining said lever incontact with said cam, and meansfor oscillating said shaft, against thetension of said yieldable means to shift the, fulcrum oflthe lever formoving the fee'd dog out of'operative working :posi- 9. In a topfeedmechanism for sewing machines, the combination with a frame in-' cludinga horizontal work support and a head disposed above the same, of a feedbar including a feed dog carried by'the head for feeding the workrearwardly between the work'support andthe head, said feed dog havingits workengaging'surface disposed in a vertical plane, a lever fulcrumedon the head and having pivotal connection with the rear end of the feed,bar for reciprocating said bar longitudinally in the line of feed, anda lever fulcrumed on the headand having a sliding connection'withthefront end of the feed for reciprocating saidbar in a plane atsubstantially right angles to its longitudi V nal axis.

10. In a top feed mechanism for sewing head and having its lower endpivotally connected to the rear end of the feed bar for reciprocatingsaid bar longitudinally in the line of feed, a link connecting theeccentric and the upper end of-the lever, alever ful crumed on the headand having a sliding con-' nection with the front end of the feed barfor reciprocating said bar'in a plane at substantially right angles toits longitudinal axis, and operating connections between said shaft andsaid second lever. Y

11. In a top feed mechanism for sewing 'machines, the combination with aframe including a horizontal work support and a head disposed above thesame, of a feed bar including a feed dog carried by the head for feedingthe work rearwardly between the worksupport and the head, said feed doghaving its work engaging surface disposed in a vertical plane, a rotaryshaft journaled in said head, an eccentric on said'shaft, a verticallydisposed lever fulcrumed on the head and having its lower end pivotallyconnected to the rear end of the feed bar for reciprocating said barlongitudinally'in the'line of feed, a link connecting the eccentric andthe 5 upper end-of the lever, a lever fulcrume'd on s the head andhaving a sliding connection with the front end of the, feedbar forreciprocating saidbar in a plane at substantially right angles to itslongitudinal axis, and operating connections between said shaft and saidsecond lever including a counter shaft, a pcripheral cam fixed on saidcounter shaft and having direct contact with said secondlever, anda-spring connecting the second lever and head for maintaining saidcontact between thelever and cam. f

12. In altop feed mechanism for sewing machines, the combination with aframe including a horizontal work support and head disposed above thesame, of a feed bar including a feed dog carried by the head for feedingthe work rearwardly between the work support and the head, said feed doghaving its work engagingsurface disposed in a vertical, plane, a leverVfulcrurne'd on the head and having pivotal connection with the feed barfor reciprocating said bar longi rock shaft, a spring connection betweenthe head and the rock shaft for yieldably retaining the shaft againstrocking movement, a lever fulcrumed on said crank pin and havingconnection with the feed bar for reciprocating the bar in a plane atsubstantially right angles to its longitudinal axis, means foroscillating said lever, and means for oscillating said rock shaftagainst the tension of said yieldable means to shift the fulcrum of thelever for moving the feed dog out of operative working position.

13. In a feed mechanism for sewing machines, the combination with a worksupport, of a presser foot having a vertical guideway extendingrearwardly from its front end, an oscillatory needle movable across theguideway, one wall of the guideway extending in rear of the path ofneedle oscillation, a four motion bottom feed cooperating with thepresser foot to feed the material along the guideway past the path ofneedle oscillation and including a feed dog having its teeth in ahorizontal plane, and a four motion top feed cooperating with the rearwall of the guideway to feed the seamed material rearwardly away fromthe path of needle oscillation, and including a feed dog having itsteeth in a vertical plane.

In testimony whereof I hereunto affix my signature.

CHARLES W. MUELLER.

